The invention which is the subject of this application relates to apparatus for lifting articles or persons between lowered and raised positions. The apparatus is provided in a lowered position to allow articles to be placed on or rolled onto a base from a surface and then raised or lowered on said base to a level to allow access of the article or person to another surface for example, such as would be used for the loading and unloading of articles onto the storage area of a lorry or trailer, or person onto rail carriages, buses or the like.
There are many different known forms of lifting apparatus, one of which is described in the Applicant""s co-pending application No. WO 9711023. In this application, there is disclosed the provision of a lifting base which is movable between raised and lowered positions and, when in the lowered position, the base can be powered downwardly to move in relation to a supporting frame which is positioned to lie close to and parallel with the surface. The base can then be further powered downwardly towards the surface and, as it does so, contacts with the surface and causes the frame to be released from the surface. The base is typically provided with wheels or rollers protruding underneath the same such that when the base is powered down towards the surface, it, and the wheels and rollers move through the aperture defined by the frame and the wheels or rollers contact with the surface. In this position, the apparatus is movable about the surface to the required location. When the base is raised, the support frame returns to contact the surface and so, when the base is being raised or lowered the frame is held in constant, fixed position on the surface. This arrangement is particularly suited for the loading of vehicles with goods from and into warehouses or delivery points and where the base is required to carry a considerable number of articles all of which are to be stored and moved into the same location.
However, one problem of the disclosed apparatus is that the wheels or rollers protrude below the base to move the apparatus, the base is raised from the floor even when in a fully lowered position and this can make it difficult for items such as trolleys, wheelchairs and the like to be rolled onto the base. Another feature which can be a problem in certain uses is that it is not possible to have the apparatus movable when the base is in a raised position as the wheels or rollers are mounted on the base itself. This can be inconvenient when the apparatus is used for more frequent loading and unloading of items such as, for example, persons on wheelchairs.
The air of the present invention is to provide apparatus which has improved utility to suit specific requirements and uses of the same.
According to a first aspect of the present invention there is provided lifting apparatus comprising a base which is movable between raised and lowered positions, a support frame in relation to which said base is movable, guide means which guide the movement of the base between raised and lowered positions, power means which allow the base to be moved and wheels or rollers which allow the apparatus to be moved along a surface and wherein at least the wheels or rollers can be moved with respect to the apparatus between an in-use position in which they contact a surface and an out of use position with the wheels out of contact with the surface.
Preferably the wheels or rollers are mounted on a portion of the apparatus and movable with respect to that portion.
In one embodiment the wheels or rollers are mounted on the support frame, and movable with respect to the support frame. In an alternative embodiment the wheels or rollers are mounted on the base, and movable with respect to the base.
In one embodiment the wheels can be moved between in-use and out of use positions such that in the in-use position the wheels protrude from the bottom of the frame to allow the same to contact with the surface and in the out of use position the wheels are retracted such that the base can be moved closer to the surface than is the case with the wheels in an in-use position and this makes it easier for the moving of goods on and off said base from the surface.
In a further embodiment the wheels can be moved between an in-use position in which the wheels contact the surface and a retracted position with the wheels above the surface and the support frame in contact with the surface. In this position, the lifting apparatus stability is improved and goods can be moved easily from the base to the surface.
In one embodiment it is envisaged that the wheels will be mounted on members which, when in the in-use position, extend outwardly from the frame so that the wheels are positioned outwith the frame when contacting the surface.
In the in-use position, the wheels contact the surface and allow the apparatus to be moved across the surface. In one embodiment the wheels can be connected to the frame so that the wheels can be moved to the in-use position regardless of the position of the base relative to the frame, and also allow the apparatus to be moved across the surface with the base in a raised position.
Typically a ramp is provided which can be folded down to improve the rolling of articles to and from the base from the surface.
The wheels can be provided in connection with the base or alternatively the wheels can be provided in connection with the support frame.
The invention allows the base to be positioned significantly closer to the surface when the wheels are in an in use position.
In a further aspect of the present invention one or more jacks are provided on the support frame and the jacks can move between a raised position, with the jacks on the surface and the frame and wheels above the surface, and a retracted position with the wheels in use and in contact with the surface and the lifting apparatus thus movable across the surface. The wheels can be mounted on members which extend outwardly when in an in use position so that the wheels lie outwith the frame when contacting the surface.
The power means to move the base between raised and lowered positions, to move the wheels between in-use and out of use positions and/or to move the one or more jacks between a raised position and a retracted position can be provided by manually operated power means or, alternatively, powered drive means can be provided such as electrically or hydraulically powered drives.
The power means to move the wheels and/or the one or more jacks can be part of the same power means as that used to move the base between raised and lowered positions or, alternatively, separate power means are provided to operate the base, wheels and/or one or more jacks.
In one embodiment it is envisaged that the apparatus is of use for disabled persons and particularly those with wheelchairs to allow movement of said wheelchairs and persons to vehicles, buses or trains. When the apparatus is provided with a powered drive, it is of course possible that the person in the wheelchair on the base can be provided with control means to allow operation by them of the movement of the apparatus across the surface, thereby allowing increased independence to the disabled user. The control means can be permanently attached to the base or to members protruding from the base or may be provided with a flexible connection which allows the control means to be used by a person standing on the base and/or on the surface adjacent the apparatus.
Another envisaged use is in conjunction with vehicle trailers to allow the loading and unloading of goods to and from the trailers in the warehouses or at delivery points. It is therefore envisaged that each delivery point can be provided with the apparatus according to the invention so that there will be no need for the tail lift apparatus which is conventionally fitted to vehicles which offers significant reductions in cost of the vehicles.
In one alternative embodiment the apparatus is provided with attachment means to allow the same to be attached to the vehicle trailer to allow the same to be carried with and/or used in conjunction with the trailer in a manner typically as that of for example a tail lift. Preferably the apparatus has the significant advantage of being disengagable and movable into the delivery area or warehouse with the goods and thus provides the combination of a loading and unloading facility, and goods moving facility which is not possible with conventional tail lifts which are permanently fixed to the vehicles.
The invention will now be described with reference to the accompanying drawings, wherein:
FIGS. 1A-D illustrate the apparatus according to one embodiment of the invention for use with a vehicle storage area; and
FIGS. 2A-D illustrate apparatus according to a second embodiment of the invention for use with disabled persons.
FIGS. 3A-B illustrates an embodiment of the invention with wheels of the lifting apparatus in retracted and in-use positions.
FIGS. 4A-B illustrates a further embodiment of the invention with jacks of the lifting apparatus in an in-use position and retracted position.